Berkeley Lab Building
Materials Pathways (B-PATH) Model
Introduction
Developed by researchers at Lawrence Berkeley National Laboratory
(LBNL), the Berkeley Lab Building Materials Pathways (B-PATH) Model
aims to enhance environmental decision-making in the commercial
building LCA, design, and planning communities through the following
key features:
1) Modeling of discrete technology
options in the production, transportation, construction,
and end of life processes associated U.S. structural building
materials. While there have been a number of stand-alone LCAs
of commercial buildings and their materials, it is often difficult
to transfer the results of these studies to assessments of
real-world buildings. Specifically, the environmental impacts
of structural materials for a given job site will depend in part on
the technology characteristics of local and regional supply chains;
these characteristics might differ from the “average” technology
assumptions used in many building LCA studies and databases.
2) Modeling of energy supply
options for electricity provision and directly combusted
fuels across the building life cycle. Most LCA models allow
for some user-defined energy supply assumptions. However,
often the LCI data in such models are not sufficiently disaggregated
into unit process technologies, whose energy use and fuel options
(e.g., alternative fuels or fuel switching) can vary in
practice. B-PATH allows for user-defined energy supply at the
process technology level, which provides greater flexibility for
modeling regional and production system energy supply variations for
structural materials.
3) Comprehensiveness of
relevant building mass and energy flows and environmental
indicators to ensure that B-PATH’s discrete technology
modeling approach allows for consideration of a range of
environmental impacts in materials selection, and for different
building elements.
4) Ability to estimate
modeling uncertainties through easy creation of different
life-cycle technology and energy supply pathways for structural
materials, and easy consideration of different methodological
assumptions (e.g., system boundaries and allocation protocols),
which can serve as bounding scenarios on environmental impacts.
5) Encapsulation of the above features in a transparent public use model,
which can be assessed and refined by the stakeholder community,
expanded to include new technology options as they emerge over time,
and can offer a fully citable public data resource.
Model development was focused on life-cycle pathways for three major
structural materials options for commercial buildings: (1)
reinforced concrete; (2) steel; and (3) lumber. The current
version of B-PATH is targeted at low-rise construction (typically
defined as 2-5 floors) due to the predominance of this building form
in the U.S. commercial sector.
Download the B-PATH Model and Report
B-PATH is available as a Microsoft Excel file, which can be
downloaded by clicking here.
The B-PATH project report can be downloaded by clicking here.
B-PATH Development Team
Alexander Stadel, Drexel University
Petek Gursel, University of California, Berkeley
Eric Masanet, Lawrence Berkeley National Laboratory and University
of California, Berkeley
Contact Information
Questions about the B-PATH model should be directed to:
Eric Masanet, Ph.D.
Staff Scientist
Energy Analysis Department
Environmental Energy Technologies Division
Lawrence Berkeley National Laboratory
Building 90R4000
Berkeley, California, USA 94720
Phone: 1.510.486.6794
Fax: 1.510.486.6996
Email: ermasanet@lbl.gov